Implantable infusions systems have been used to treat a variety of diseases, such as spasticity, pain and cancer by targeting drug delivery to a selected area of a patient. Therapies employing such systems have proven to be very helpful for patients for whom systemic therapy is not effective, possible, or practicable. The implantable systems typically include an implantable infusion device containing a reservoir for housing the drug and a catheter coupled to the reservoir to direct the drug to the target area. The devices typically include a pump or mechanism for driving fluid from the reservoir, or withdrawing fluid from the reservoir, and through the catheter to the selected area of the patient.
A variety of catheters have been used or proposed for use in implantable infusion systems. Each type of catheter has unique properties, such as compliance and resistance to bursting under pressure. While not common, implanted catheters that are operably coupled to implantable infusion devices may become occluded. Because each type of catheter has a different resistance to bursting, often only more robust and less compliant catheters are used so that the possibility of rupturing is reduced or eliminated. However, it may be desirable to use less robust or more compliant catheters in some situations; as such catheters may be softer or thinner and may cause less damage to tissue when implanted.